The chemistry of the primary photochemical event in the visual pigment rhodopsin is being investigated by picosecond absorption spectroscopy. Attention is focused upon the feasibility of an electron followed by a proton transfer as the primary steps. The approach utilizes studies of model compounds such as retinal and the Schiff base of retinal with various electron donors, amines and phenols. Also the environmental effects on the kinetics of rhodopsin and its isomer, isorhodopsin, are being examined.